What does the white wire clip to?

I think I got a big problem. I tried soldering a prong to the back of the updated new voltage limiter to look like the old one so I could run the ground to it. The problem is I couldn't get the rosin to stick. So I figured I'd just connect the black ground wire to the circuit board off one of the prongs. So I tried grounding the black wire to the red wire connection off one of the studs on the back of the same side of the board that the voltage limiter is on. Well as soon as I hooked up the battery I saw smoke coming from the engine compartment fire wall circuit board. I quickly disconnected the battery and it stopped. I mean the battery was probably hooked up for 1 second. Then I removed the ground wire and figured start back at square one. Well I reconnected the battery and I don't have any juice to the cluster at all and my dome light won't come on. No headlights nothing. How much damage did I cause? What a mess. What have I done? Is there any way to trace the problem?

Carl